Screw and gear making- apparatus



May 17, 1927. l629123 H. J. SCHMICK SCREW AND GEAR MAKING APPARATUS Filed Senn 12. '1925 3 sheets-sheet l May 17, 1927. 1,629,123

H. Jv SCHMICK SCREW AND GEAR MAKING APPARATUS Filedsem. 12. 1925 sheets-sheet 2 www @M7 1,629,123 May 17 1927' H. J. scHMlcK SCREW AND GEAR MAKING APPARATUS Filed sem, 12. 1923 s Sheets-sheet 3 L VOTML LAVERAL :55.2, Mun/m7 Patented May 17, 1927.

ijhiiii STA'EES HENRY J". SGHMICK, OF WILLIAMSPORT, PENNSYLVANIA. i

SCREVJ AND GEAR MAKING APPARATUS.

Application inea september 12, 192s. semaine. 662,33?.

rFhis invention relates to the production ot angle gears, screws, grooved cams and similar devices for transmitting power and converting motion involving'` movements partly sliding Vand partly rolling in their nature. Examples of such articles are described in my Patent Numbers 1,432,621, 1,482,622 and 1,432,623, granted February 5, 1924 of which this application isin part a continuation, and are-characterized by working faces comprising spaced plane seg ments of uniform angular disposition and eccentric-ity with reference to the axis ot rotation. This invention aims to produce articles having the desired characteristics by simple, self compensating means easily adjustable and adaptable to various sizes and shapes asmay be desired.

Suitable apparatus for accomplishing the desired aims, such as that illustrated in the Vaccompanying drawings, forms part of the invention, although the invention is not restricted thereto. In the drawings,

Fig. 1 is a plan view of a jig or combined work holder and indexing mechanism fora milling machine type of apparatus; Figs. 2 and 3 are vertical sections of the same, on the lines 2-2 and 3-3 in Fig. 1, respectively;

Figs. 4, 5 and 6 are views similar yto Figs. 1, 2 and 3, illustrating another form of jig suitable for performing the` invention; 35 Figs. 7, 8, 9, 10 and 11 are diagrams illustrating various advantages of the invention.

r1`he work carrying and indexing device shown in Figsil, 2 and 3 may be mounted on any movable or sliding support, such as the sliding table 14 ot the machine illustrated in my Patent No. 1,482,621, whereby the work blank 11 may be repeatedly presented to the operation of the cutter or cutters 15, which are mounted tor rotation above the work in any suitable manner. l

This work supporting device comprises a guide trame 10 adapt-ed to be pivotally mounted or secured upon the tablevor support 14 by clamps or T-bolts, so as to hold the work blank at any desired angle ot traverse with reference to the direct-ion of cutting movement. The guide trame is protions at the same speed.

vided with slideways or rails for mounting a main sliding trame 13 and which in turn 55 is provided with slidewaysior the slide 40 which carries the work blank arbor 12.

The work and arbor are held in proper angular position circumiierentiaily by means of pinions 38 on the en ls of the arbor 60 which engage with racks 39secured to the frame 13. The pinions 38 may be changedV to suit the work, the racks being adjustable vertically by any suitable means in order to mesh properly. .Slots are lett in the `sides of the frame 13through which the ends of the arborproject in order to per! mit the arbor to move-with the slide. The slide 40 is moved by a .screw 41 iiXed to the slide and engaging a nut 42 rotatably mount- 70 ed on the frame 13. The pinions 38rol1 on the racks 39 as the slide movesand thereby turn the arbor proportionally toV the amount of movement of the sli-de.

The nut .42 may be adjusted by hand to feed or position the slide 40 and work'blank between cuts, or it may berotated by any suitable automatic means, such as that described in my patents referred to above.

The sliding trame 13 is moved in syn- 90 chronism with the slide 40 by means ot a screw G6 rotatably secured to it at one end and engaging a nut 67 secured to the reciprocatory supporting table 14 at the pivotal a-Xis 68 ot' the guide'frame 10. `The screw 85 66 is rot-ated by suitable changeable gears 69, 70, from the nut 42, the gears shownA being of the same pitch diameter whereby the screws are rotated in opposite direc- The apparatus illustrated in Figs; 4, 5 and 6 is similar to that illustrated in Figs. 1, 2 and 3, differing in having racks 39` arranged below the gears 38 on theworl arbor 12, and in having right and left 95 screws and changeable gears 69', 70', with pitch diameters bearing the ratio two to one for operating the screw 66. Provision is made whereby the racks may be arranged either above or below the gears 33 in either 10o apparatus and adjusted to suit the size gears it is desired to use.

The manner of operating the apparatus for performing the process is as follows: First the guide trame 10 is set at the de- 105 sired angle otcut (see Figs. 1 and 4) and the work blank 11 is mounted on the arbor 12 and the slide 40 set at one end of the main sliding frame 13 which in turn is set at the corresponding end ot' the guide frame 10 in the arrangement illustrated in Fig. 1, and at opposite ends of each in the arrangement illustrated in Fig. 4. Then the table 14 is moved orfed either automatically or by hand forward and back to cause the cutters to make a series of cuts 71, the blank 11 occupying the position lshown in dotted lines, as illustrated in Fig. 10; following which the nut 42 is turned to advance or1 ush back the slide 40 slightly, thereby ro ling the gears 38 on the racks 39 and rotating the arbor 12 so as to move the Workblank ahead as shown in :full lines ready lfor the next Series of cuts'72.

In the form of apparatus illustrated in Figs. 1, 2v and 3, lthe racks 39 and gears 38 considered bythcmselves would operate to reverse `the forward movement of the top of the workvblank due to rolling" forward as a whole, leaving the ciitslobliquel'y behind their position when cut; butl the rotation ofthe screw 66 serves to lmove the slidable support carrying the racks and gears forwards a like amount, lthereby displacing the work as a` whole forward and laterally,

and causin the succeedinflr line of cuts to be spaced circumferentially substantially in angular alinement with the first line, as shown in 10. i y

In Ethe form of apparatus illustrated in Figs. 4,5 ande, the lrolling on the racks causesyforward"movementof the topl of the workllolanky approximately double'lthe advancing'movement ofthe slide, thereby moving theseries of cutsf to the positions shown dotted lines 73 in Fig. 11; and turning .tlienut 42 causes the gears 69', 70, to` rotate the sc rewf lthrough twice the angle lturned by the nut, Awhereby the'inain sliding frame 13 is moved` backward twice 'the distancewmoved bythe slide, and the cuts are returned to approximately( their original position lengthwise of the direction of cut, but ybecause of thelrotation ofl the y,blank andthe angularity of the guide frame w10 they are displaced slightly axially and circumferentially so as to line up angularly with thenext succeeding cuts 711 made by thefsame cutters, asillustrated in Fig. 11. Repetitionof the cutting and indexing produces a series ofv parallel grooves 75 formed by `thehmerging of the successive cuts, and when, continuous around the blank these groovesv constitute gear teeth 7G, as illustrated in Figs. 7 and 8. f

ySuccessive cuts form angular-ly disposed segmental surfaces 77 (see FigfS) which intersectalong straightlines advancing on one vslide and retreating "on the other side with reference to the direction ofthe groove asv they approach the circumference and havhence the rolling length and lateral displacement of the work blank due to rolling action,

depends upon the pitch diameter of the gears 38; yand the lateral displacement due to sliding de pendsupon the ratio of the gears 69, 70, as well as upon the angle ot the guidewfi'anie. By increasing oi decreasing the sizeof these gears 38 from that of the blank, or by changing the ratio of the gears 69, 70, the lead may be shortened or lengthened, thereby condensing or expandingl the relative spacing ofthe cuts laterally and diminishing or increasing the slope of the side walls with reference to a kplane pei'- pendicular to the axis, without changingthe angle of cut, Hence it is possible to produce a gear or the-like .having a groove or tooth advancing in oneturn through an axial distance of two or more times the lead of an ordinary helical tooth having the same angle of pitch line with respect to the axis of the cylinder as the angle of cut.

Also, by changing the angle of setting of the for `the saine size work and same working length of rack thelead and/angle of cut can be varied between ,wide limits, and by reversing the angle of setting of the jig, as shown in dot and dash lines in Fig. 1, matingjtoothed gears of` opposite Idirection of lead can be generated havingv any desired angle of working face within the capacity ofthe dimensions of the machine. By setting the at first one and then the other of tivo coinplen'ientary angles `mating toothed angle gearing any desired ratio ofllteeth and pitch diameter may be generated. y This illustrated in Fig. fi, wherein the work is shown in full linesf set Vat a cutting angle ofapproxiinately I25O and in dot and dashilines at Gxfroni the normal tangent to the work cylinder. y i

Also, if the'length ot' the working portion ofthe vracks 39 andldiameter: of thegears mrolliiigA kthereon be changed to `suit the change in the angle of the guide frame 10 so as to maintain the total lateral displacementdue toprolling andsliding uniform, `the slope of the sides of the-'teeth mayl be in- 11"` and 12l` and the/lateral displacement 4 in each case, the resulting angle ofzcut being illustrated by the lines marked 8. 9,

10, 11 and 12 respectively.` The best results Milo 4tive lengthv of rack 'is shown as 8, 97 10, y

are obtained with an obliquity such that'the working length of the rack for the lead ydesired is about one-half the circumference` of the work blank in the arrangement illustrated in Figs. 1, 2 and 3, and about equal llt) to thecircumference in the arrangement illustrated inFigs. t, and 6. i

It is obvious from the foregoing description thatthe angulaisetting ot Vthe main supporting tramo l0, the relationship between the diameter o'l' the work and the pitchdiameter of the gears 88 that control its angular position and the ratio et gearing between the screw il 'for moving the main sliding frame 13 and the vscrew 6G Ylor moving the work carrying slide at), each and all may be varied so as to producearticles having anydesired angle ot cut and circin'nferential and lateral spacing of successive cuts.

The principles underlying` my invention may be understood byreference to my Patent No. 675,020, for radiohelical cam, the present invention comprising a multiplicity of such cams angularly disposed and displaced both axially and circumterentially in quadrants oli reversed angularity in bal- `anced relation aroimd the screw gear or cam,

and constituting an'oblique, multiple lace combined axial and radial rotary motion device whiclrmay for convenience be termed a progressive radiohelical cam gear.

Figs. 7, 8, 9, l0, 11,12 and 13 are tor the purpose oi illustrating diagrammatically the appiicationoit these principles to the present invention, the diagrams being imaginative merely and not representing exact dimensions or shapes oit.' a marketable product.

Having described a preferred mode oil carrying out the invention, without restricting the invention thereto, what l claim and desire to secure by Letters Patent is as follows:

fl. ln the manufacture ot articles oi the character described, a cutter having a lined direction of cut, means for rotatably and slidably mounting a. work blank ttor engagement by said cutter at the cutting` point, said means being pivotally supported whereby the direction of sliding motion may be adjusted to suit the work in hand, and means 'tor causing said work blank to roll in the line of direction ot its sliding moven'ient, said rolling means acting in opposition lo said slidingI means to return the work to the cutting point.

2. lii the manufacture oi articles oi' they character described, a cutter having a fixed direction ot' cut means lfor rotatably and slidably mounting` a work blank ttor engagement by said cutter at the cutting poi-nt, said means being pivotally supported whereby the direction of sliding motion may be adjusted to suit the work in hand, and means for causing saidwork blank to roll in the line ot direction olf its sliding movement, said rolling means acting in opposition to said sliding means to return the work to the cutting point, and means for maintaining said opposed movements in apredetermined rat-io suitable For the workin hand.

3; fr work support `coniprising a guide trarne adapted to' be `adjusted angular-ly around a vertical main supporting traine movably mounted on said guide iirame,fa slide carried by said supporting frame and slidable in ythe same direction as the guide traine, means ior moving said iframes simultaneously causingmovement oi vsaid slide upon said supporting frame in ylaterally with a combined rotating and rolling motion, and gearing carried kby said main supporting traine and slide for positioning the slide on the supporting 'frame and supi'iorting frame on the guide trame.

5. ik jig comprising a guide frame, a main supporting frame mounted thereon carrying a slidable work support, rotatable means on the work support ilor carryingl the work, said rotatable means having a pinion engaging a rack on the main supporting iframe wherebyT when the work is rotated it is moved laterally with a combined rotating and rolling motion, and gearing carried by said main supporting frame and slide 'tor positioning the slide on the supporting frame and supporting trame on the guide trame, said gearing comprising lead screws carried by said slide and main supporting fra-me respectively and respectively engaging said main supporting frame and guidey frame for positioning said movable members relatively to each other and the fixed support, and changeable vgears operatively connecting said lead screws.

(l. A comprising a guide frame, a main supporting frame mounted thereon carrying a slidable work support, rotatable means on the work support for carrying the work, said rotatable means having a pinion engaging a rack on the main supporting frame whereby when the work is rotated it isl 7. Apparatus of the character described comprising a cutting point, a guide `frame pivotally adjustable thereto, a main supporting frame inovably mounted thereon carrying a slidable work support, said main supporting frame andwoilsiippoit' being connected to move in unison upon Said guide frame,l and rotatable means'onsaid work support `for positioning Athe work circumferentially, said rotatable means andiniain supporting framey being operativelypkconnected to control the circumferential position of said workby therelative position of saidlwork support onsaid main supporting frame.

V'8.V4Apparatus for the production of Aprogressive radio-helical cam gears V.having grooved working portions characterized by straight 4part segmentswarranged .eccentrically at angles lessv than' the normal .slope ofy thelsurfaces formed thereby, comprising means for .providing a seriesofspacedtransverse lcuts,` oblique `and eccentric to the axis of rotation,` in combination with means for dis lacing successive lcuts circumterentiallv an Ilaterallywas by rolling the article tov move said ,cuts in one directionV along a path'transverse to its axis and sliding it in v tent of sliding relative to rolling movement is approximately the same.

ll. lApparatus for `the production of articles as described in claim '8 wherein the Obliquity of the angle of cut is approximately the same as that of the direction ot' rolling.

l2. Apparatus for the production of articles as described inl claim 8 l wherein the obliquity of the angle of cut issuch as produces the :desired lead vwith a yrolling move-- ment approximately the saine as the circumference of theblank.

In testimony whereotl have signed my name to this Specification.

lHENRLT J. SCHMICK. 

